1. Field of the Invention
This invention relates to fluorophosphate based optical components with improved optical characteristics for use in high energy environments.
2. Description of Related Art
Some of the known conventional optical components have some levels of radiation resistance, but that level of resistance is not sufficient for their use in high energy environments.
Examples of optical components with different levels of radiation resistant characteristics can be seen in bismuth metaphosphate based glass systems that solarize after being exposed to a few hundred kilo rads of gamma radiation. Other examples include the SiO2 base optical components, which are well-known as poor performers under high energy environments in that they darken under very low levels of gamma radiation, making them very impractical for uses in high energy environments. Other optical components comprised of phosphate based glasses of varying compositions contain alkaline elements, which are also known to actually reduce and lower the overall radiation resistance of the final product, thus rendering them very impractical for use in any high energy environments. Other optical components used include the germanium dioxide based network structures, which are not suitable for radiation resistance due to the presence of GeO2.
With respect to the optical characteristics of the above optical components and, in particular in relation to their surface laser damage threshold, most have a very low surface laser damage threshold as indicated in the following table:
Surface Laser Damage ThresholdOptical ComponentSurface Laser damage thresholdSchott glass Products~30J/cm2phosphate glasses LG750Corning glass products silica~38 +/− 2J/cm2glasses 7940Corning glass products borosilicate~32J/cm2glass 0211Bismuth containing fluorophosphate~29J/cm2glass
Therefore, the above optical components cannot be used in high laser energy environments, which requires thresholds that are 60 J/cm2 or higher.
Accordingly, in light of the current state of the art and the drawbacks to current optical components, a need exists for an optical component that would have a high-energy resistance and superior active and passive optical characteristics.